Settings for Gregorian chant in the style of a medium Pontificale.

pontificale-chant.tex

% !TEX program = lualatex
% !TEX encoding = UTF-8

\documentclass[20pt, extrafontsizes]{memoir}

\usepackage[letterpaper,vmargin={1in,1in},hmargin={1in,1in}]{geometry}

\usepackage{fullpage}
\usepackage{microtype}
\usepackage{fontspec}

\usepackage{gregoriotex}
\gresetlinecolor{gregoriocolor}
\grechangestaffsize{27}
\gresetlinesbehindpunctumcavum{visible}
\grechangestafflinethickness{50}
\grechangedim{spacelinestext}{2.7ex}{fixed}
\grechangedim{spaceabovelines}{1.9ex}{scalable}
\gresetgregoriofont[op]{greciliae}

\usepackage[latin]{babel}

\usepackage{fontspec}
\defaultfontfeatures{Ligatures=TeX}
\setmainfont{Libertinus Serif}
\usepackage{Carrickc,lettrine}
\renewcommand\LettrineFontHook{\Carrickcfamily}

\pagestyle{empty}
\begin{document}
\setlength{\parindent}{0pt}
\gresetbracerendering{font} 
% Your Chant here...
\end{document}